Off-board gyrocopter take-off systems and associated methods

ABSTRACT

Off-board gyrocopter take-off systems and associated methods are disclosed. A representative method includes restraining a gyrocopter from vertical and lateral movement, pre-rotating a fixed-pitch lift rotor of the gyrocopter via a power source located off the gyrocopter, and releasing the gyrocopter for vertical movement to allow the gyrocopter to lift under a force provided by the lift rotor. Optionally, the method can further include interrupting or reducing power from the power source to the gyrocopter as a way to release the gyrocopter for vertical movement.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/602,190, filed Jan. 21, 2015, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure is directed generally to off-board gyrocoptertake-off systems and associated methods. The technology can be appliedto manned and/or unmanned gyrocopters.

BACKGROUND

A gyrocopter is an aircraft that flies using a combination of a poweredpropeller and an unpowered set of rotary wings. The propeller providesthe aircraft with forward thrust, and the rotary wings (or rotor)autorotate to generate a lift as a result of the forward thrust of theaircraft. Unlike a helicopter, a gyrocopter typically requires somelength of runaway for both take-off and landing. Unlike a fixed wingaircraft, the ability of the rotor to autorotate as the gyrocopter gainsforward speed significantly reduces the distance required for bothtake-off and landing.

One approach used to further reduce the gyrocopter's take-off andlanding distance is to pre-rotate the rotor so that it begins generatinglift before the gyrocopter begins to move in a forward direction. In atypical arrangement, a gyrocopter pre-rotator uses power from thegyrocopter engine (which otherwise produces power for the thrustpropeller), for example, via a clutched drive drum or drive wheelcombination. The drive system typically includes a drive shaft having afirst gear that engages with a corresponding second gear carried by therotor. The drive system can include a flexible shaft or a fixed shaft,such as a shaft coupled between universal joints.

One drawback with the foregoing approach is that the gyrocopter rotortypically has a fixed pitch. As a result, the lift generated by therotor (when powered by the pre-rotator) is typically not enough toeliminate the need for a runway. Accordingly, one approach to addressthe foregoing problem is to provide the rotor with a collective pitchcontrol. In operation, the pitch control is initially set to zero pitchto reduce the drag on the rotor and reduce the requirements for spinningthe rotor up. Once the rotor has been spun up, the pitch of the rotorblades is suddenly increased, causing the gyrocopter to rise suddenly ina “jump take-off” maneuver.

However, the “jump take-off”system also has drawbacks. For example, thisapproach can significantly increase the complexity of the rotor headbecause the rotor head must be configured to pitch the rotor blades. Asa result, the initial cost of the gyrocopter and the level ofmaintenance required to keep the gyrocopter in operation may increase tothe point where the gyrocopter is nearly as costly as a helicopter. Insuch instances, many commercial operators prefer a helicopter, whichdoes not need a pre-rotator for zero distance take-offs. Accordingly,there remains a need for cost-effective gyrocopters that require notake-off or landing roll.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic, side isometric view of a system thatincludes a gyrocopter and a pre-rotator that is carried, at least inpart, off the gyrocopter, in accordance with an embodiment of thepresent technology.

FIG. 2 is a partially schematic, front isometric illustration of thesystem shown in FIG. 1.

FIG. 3 is a partially schematic, side isometric illustration of theoff-board portion of the system shown in FIGS. 1 and 2, configured inaccordance with an embodiment of the present technology.

FIG. 4 is a partially schematic, isometric illustration of anarrangement for releasably coupling the off-board and the on-boardportions of a pre-rotator system in accordance with an embodiment of thepresent technology.

FIG. 5A is a partially schematic, front isometric illustration of asystem that provides power for a pre-rotator from both on-board andoff-board the gyrocopter, in accordance with an embodiment of thepresent technology.

FIG. 5B is a partially schematic, front isometric illustration of asystem that includes power for a pre-rotator supplied from both on-boardand off-board the gyrocopter in accordance with another embodiment ofthe present technology.

FIG. 6A is a partially schematic, side isometric illustration of agyrocopter and pre-rotator system configured in accordance with anotherembodiment of the present technology.

FIG. 6B is an enlarged, front isometric illustration of the arrangementshown in FIG. 6A.

FIG. 6C is an enlarged illustration of a rear portion of the gyrocoptershown in FIGS. 6A and 6B.

FIG. 7A is a partially schematic, side elevation view of a pre-rotatorsystem configured in accordance with still another embodiment of thepresent technology.

FIGS. 7B is a front view of the system shown in FIG. 7A.

FIG. 8 is a partially schematic side elevation view of a systemconfigured to restrain a gyrocopter having skis or skids, in accordancewith still another embodiment of the present technology.

FIG. 9 is a flow diagram illustrating a representative process forpre-rotating a gyrocopter rotor in accordance an embodiment of thepresent technology.

DETAILED DESCRIPTION

The present technology is directed generally to off-board gyrocoptertake-off systems, and associated methods. Specific details of severalembodiments of the disclosed technology are described below withreference to particular, representative configurations. In otherembodiments, the disclosed technology can be practiced in accordancewith gyrocopters and associated systems having other configurations.Specific details describing structures or processes that are well-knownand often associated with gyrocopters, but that may unnecessarilyobscure some significant aspects of the presently disclosed technology,are not set forth in the following description for purposes of clarity.Moreover, although the following disclosure sets forth severalembodiments of different aspects of the disclosed technology, severalother embodiments of the technology can have configurations and/orcomponents different than those described in this section. As such, thepresent technology may have other embodiments with additional elements,and/or without several of the elements described below with reference toFIGS. 1-9.

Several embodiments of the disclosed technology may take the form ofcomputer-executable instructions, including routines executed by aprogrammable computer or controller. Those skilled in the relevant artwill appreciate that the technology can be practiced on computer orcontroller systems other than those shown and described below. Thetechnology can be embodied in a special-purpose computer, controller, ordata processor that is specifically programmed, configured orconstructed to perform one or more of the computer-executableinstructions described below. Accordingly, the terms “computer” and“controller” as generally used herein include a suitable data processorand can include internet appliances and hand-held devices, includingpalm-top computers, wearable computers, cellular or mobile phones,multi-processor systems, processor-based or programmable consumerelectronics, network computers, mini computers and the like. Informationhandled by these computers can be presented at any suitable displaymedium, including a liquid crystal display (LCD). As described furtherbelow with reference to FIG. 1, the term “controller” can also includemechanical and electromechanical devices.

The present technology can also be practiced in distributedenvironments, where tasks or modules are performed by remote processingdevices that are linked through a communications network. In adistributed computing environment, program modules or subroutines may belocated in local and remote memory storage devices. Aspects of thetechnology described below may be stored or distributed oncomputer-readable media, including, magnetic or optically readable orremovable computer discs, as well as distributed electronically overnetworks. Data structures and transmissions of data particular toaspects of the technology are also encompassed within the scope of thepresent technology.

FIG. 1 is a partially schematic, side isometric illustration of anoverall system 100 that includes a manned or unmanned gyrocopter 110configured to take off with no requirement for a runway or othertake-off path. Instead, the gyrocopter 110 can include a lift rotor 112that lifts the gyrocopter vertically. In a further aspect of thisembodiment, the lift rotor 112 has fixed-pitch blades 119 instead ofvariable-pitch blades. The fixed-pitch blades 119 can be powered by apre-rotator 120. The pre-rotator 120 includes on-board pre-rotatorcomponents 130 and off-board pre-rotator components 140 that arereleasably coupled together to launch the gyrocopter 110 into verticalflight without a runway and without pitchable lift rotor blades. Oncethe gyrocopter 110 is launched (or as part of the launch process), theon-board pre-rotator components 130 disengage from the off-boardpre-rotator components 140, and the gyrocopter 110 continues its flight.

In a particular embodiment, the gyrocopter 110 includes a body orfuselage 111 that supports the lift rotor 112. The lift rotor 112 canhave a “teeter-totter” arrangement that allows it to tilt significantlyrelative to the vertical axis V of the vehicle, so as to auto-rotate andprovide lift during forward flight. Because the rotor 112 can have afixed-pitch configuration, the individual blades 119 do not change pitchrelative to each other, even as the rotor 112 itself tilts.

The thrust for forward flight is provided by a propeller 113 which iscoupled to an on-board power source 114 (e.g., a first power source).The on-board power source 114 can include an electric motor, an internalcombustion engine, or another suitable engine configured to providesufficient power to the propeller 113. During normal flight, thepropeller 113 is powered and the lift rotor 112 is unpowered, as istypical for a gyrocopter configuration.

The gyrocopter 110 can further include landing gear 117 (e.g., wheels118, skids, and/or other suitable devices). In particular embodiments,the landing gear 117 are restrained during a pre-rotation operation, aswill be discussed in further detail below. The gyrocopter 110 can alsoinclude a tail boom 115 and a vertical stabilizer 116 to provide forlateral stability and control.

The on-board pre-rotator components 130 can include an on-boardtransmission device 131 having a first coupling 133 that transmits powerto the lift rotor 112. Accordingly, the lift rotor 112 can include acorresponding rotor coupling 132 that engages with the first coupling133. In a particular embodiment, the first coupling 133 includes a gearor sprocket, and the rotor coupling 132 includes a corresponding,meshing gear or sprocket. The first coupling 133 can be selectivelydisengaged from the rotor coupling 132, e.g., to allow the rotor 112 totilt, and/or to reduce wear on the on-board transmission device 131 whenthe pre-rotator 120 is not in use. In other embodiments, an arrangementof pulleys and belts, including a tensioning or “swinging” pulley, isused to connect the lift rotor 112 and the on-board transmission device131, and to account for relative motion between the two, In stillfurther embodiments, the rotor coupling 132 and the first coupling 133can remain engaged, and power supplied to the on-board transmissiondevice 131 is controlled via clutch. The transmission device 131 caninclude a flexible coupling arrangement, e.g., a flexible cable or shaftthat rotates within a flexible sleeve or housing, generally similar inoperation to a tachometer or speedometer cable. In other embodiments,the transmission device 131 can include other suitable arrangements thatprovide sufficient torque to the rotor 112. Such arrangements caninclude multiple fixed shafts coupled in series with universal joints,among other arrangements. In any of these embodiments, the on-boardtransmission device 131 can include a second coupling 134 (e.g., anon-board coupling) that receives power from the off-board pre-rotatorcomponents 140 during the pre-rotator operation.

The off-board pre-rotator components 140 can be carried by a base orsupport 141, or can have other locations or positions that are off thegyrocopter 110 (e.g., directly on the ground or on another vehicle). Theoff-board components 140 can include an off- board transmission device146 that releasably couples to the second coupling 134 of the on-boardtransmission device 131. The off-board transmission device 146 can alsobe coupled to a motor or other off-board power source 145 (e.g., asecond power source), both of which can be carried by the base 141. Thebase 141 can be releasably attached to the ground, using suitabletie-downs, weights, or other arrangements. In other embodiments, thebase 141 can be carried by a separate transport vehicle, for example, atruck. The base 141 can remain onboard the transport vehicle duringoperation, or it can be taken on and off the transport vehicle betweenoperations. In any of these embodiments, the off-board components 140can also include a restraint system 142 that keeps the gyrocopter 110 inposition while the lift rotor 112 is spun up for take-off. In aparticular embodiment, the restraint system 142 can include one or morevertical restraints 143 and/or one or more lateral restraints 144. Therestraint system 142 is accordingly configured to prevent or at leastsignificantly restrict the gyrocopter 110 from lifting, moving laterally(forward, backward and/or side-to-side), and/or rotating while the liftrotor 112 is spun up.

The operation of the system 100 can be controlled by a control system170. The control system 170 can include an on-board controller orcontroller components 171 and/or an off-board controller or controllercomponents 172. The controllers/components 171, 172 can communicate witheach other and/or with other systems or system components via a wirelesscommunication device 147. The controllers/components 171, 172 caninclude mechanical controls, electrical controls and/or digitalcontrols, and can respond to inputs (e.g., sensor inputs) with outputs(e.g., command signals) using software, firmware and/or hardware that isconfigured and/or programmed to carry out the planned actions. Theplanned actions can include starting, stopping, accelerating and/ordecelerating the off-board power source 145, engaging and disengagingthe restraint system 142 and/or engaging and disengaging the on-boardtransmission device 131 and the off-board transmission device 146. Inaddition, the controllers/components 171, 172 can carry out otherfunctions, for example, controlling the on-board power source 114 and/orother functions, for example, if the gyrocopter 110 is unmanned.

FIG. 2 is a partially schematic, front isometric illustration of thesystem 100 described above with reference to FIG. 1. As shown in FIG. 2,the off-board transmission device 146 can include a first coupling 148(e.g., an off-board coupling) that is releasably coupled to the secondcoupling 134 (e.g., the on-board coupling) of the on-board transmissiondevice 131. The off-board transmission device 146 can further include asecond coupling 149 that is connected to the off-board power source 145.

As is also shown in FIG. 2, the restraint system 142 can include thelateral restraints 144 (e.g., having an upright flange configuration orother suitable configuration) that engage with the sides of thegyrocopter wheels 118 and/or other portions of the landing gear 117. Thevertical restraint 143 can include an arrangement of clamps that bothhold the wheels 118 down (e.g., by engaging surfaces of the wheels thatface at least partially upwards) and prevent the wheels 118 from rollingforward. Accordingly, the combination of the vertical restraint 143 andthe lateral restraint 144 can prevent the gyrocopter 110 from movingforward, laterally, upwardly, and rotationally about the vehiclevertical axis V. In an embodiment shown in FIG. 2, the restraint system143 applies a restraining force to all three wheels 118 of thegyrocopter 110. In other embodiments, the restraint system 143 can applya restraining force to fewer wheels 118 and/or to other landing gearand/or to other (non-landing gear) components of the gyrocopter 110.

FIG. 3 is a partially schematic, side isometric illustration ofrepresentative off-board components 140 of the system 100. For purposesof illustration the gyrocopter shown in FIGS. 1 and 2 is not shown inFIG. 3. As is shown in FIG. 3, the vertical restraint 143 can includemultiple, pivoting engagement elements 151 that can pivot inwardlytoward a closed, engaged, or capture position, as indicated by arrows Cto engage with the wheels 118 (FIG. 2) of the gyrocopter 110. Theengagement elements 151 can pivot outwardly as indicated by arrows O torelease the gyrocopter. The off-board transmission device 146 caninclude a flexible link, for example, having a cable or shaft within asleeve configuration generally similar to a speedometer cable ortachometer cable, as described above with reference to the on-boardtransmission device 131. In other embodiments, the off-boardtransmission device 146 can have other suitable arrangements, forexample, a fixed shaft arrangement. In any of these embodiments, theoff-board transmission device 146 can include an intermediate coupling152 that provides a link between the first coupling 148 (which engageswith the gyrocopter) and the second coupling 149 (which engages with theoff-board power source 145).

In particular embodiments, the system 100 can include one or morerelease mechanisms 150 that disengage the restraint system 142. Arepresentative release mechanism 150 includes an arrangement of cables,powered solenoids, and/or other mechanical or electro-mechanical devicesthat change the configuration or state of the restraint system 142 froman engaged configuration or state to a disengaged configuration orstate, and back again. The release mechanism 150 can be triggeredmanually, automatically, or via a combination of manually andautomatically operated elements. For example, when the release mechanism150 is to be engaged or disengaged, this operation can be triggeredautomatically from the ground or from the gyrocopter itself, with orwithout manual input depending on the embodiment. In any of theforegoing embodiments, the release mechanism 150 can be changeablebetween a first configuration in which it is positioned to restrain orat least partially restrain the gyrocopter 110 from movement, and asecond configuration in which the release mechanism 150 is positionednot to restrain the gyrocopter 110.

As discussed above, one feature of the pre-rotator 120 is that itincludes a releasable transmission link between pre-rotator componentslocated on the gyrocopter 110 and pre-rotator components located off thegyrocopter 110. FIG. 4 illustrates a representative arrangement of sucha device. As shown in FIG. 4, the gyrocopter 110 and its associatedon-board transmission device 131 can include a shaft 136 that projectsoutwardly from the lower surface of the gyrocopter body 111. The shaft136 can be supported by a bearing 135, and can include or be connectedto a male spline element 137 that forms the second coupling 134. Theoff-board transmission device 146 can include a complementaryarrangement. Accordingly, the off-board transmission device can includea female spline element 153 that forms the first coupling 148 and thatis carried by the base 141. A corresponding bearing 154 supports thefemale spline element 153 and allows it to rotate and transmit torque tothe male spline element 137 when the two are engaged.

During operation, the gyrocopter 110 can be positioned relative to thebase 141 so that the male spline element 137 engages with the femalespline element 153. This can be accomplished by setting the gyrocopter110 down in the appropriate position and/or by translating thegyrocopter 110, depending upon the relative orientation of the malespline element 137 and the female spline element 153. In any of theseembodiments, the male and female spline elements 137, 153 maintainengagement with each other until the pre-rotation process has beencompleted.

As discussed above, the gyrocopter 110 can be held in position duringthe pre-rotation process via the restraint system 142 (shown in FIGS.1-3). The restraint system 142 can be actively engaged (e.g., via one ormore actuators) prior to the pre-rotation process, and activelydisengaged once the gyrocopter rotor 112 has been spun up to a suitablerotation rate. In another embodiment, the ground-based first coupling148 and the gyrocopter-based second coupling 134 can provide both atorque-transmitting function and a restraint function. Accordingly, theseparate restraint system 142 can be simplified or eliminated. In aparticular example, the friction between the male spline element 137 andthe female spline element 153 (while the first coupling 148 isaccelerating) can be sufficient to prevent the gyrocopter from liftingfrom the base 141 and thereby disengaging the male spline element 137from the female spline element 153. Once the gyrocopter rotor 112 hasbeen accelerated to a sufficient rotational speed, the controller caninterrupt or reduce the power provided to the first coupling 148 by thepower source 145 (FIG. 3). At that point, the first coupling 148 is nolonger accelerating, and the frictional forces between the female splineelement 153 and the male spline element 137 decrease to the point atwhich the gyrocopter 110 begins to lift. As the gyrocopter 110 lifts,the male spline element 137 disengages from the female spline element153. This arrangement can accordingly eliminate the need for a separateactuatable vertical restraint. In at least some embodiments, the base141 may still include one or more lateral restraints 144 (FIG. 3) toprevent the gyrocopter from rotating. A similar restraint, albeit apassive restraint, can be positioned forward of the wheels 118 toprevent the gyrocopter from rolling forward during the pre-rotationprocess.

In other embodiments, the system can include other configurations thatperform some or all of the functions described above. For example, FIG.5A illustrates a system 500 a for which the vertical restraint isprovided by a ring 529 or other element projecting downwardly from thegyrocopter 110, which is engaged by a hook 555 or other element. Thehook 555 can rotate on a pivot pin, as indicated by arrow R.Accordingly, the hook 555 can engage the ring 529 to restrain thegyrocopter 110 from vertical motion, and can disengage from the ring 529to allow the gyrocopter 110 to lift. Optionally, the lateral restraints144 can remain to prevent rotational movement of the gyrocopter. Inanother embodiment, the downward force provided by the hook 555 and itsengagement with the ring 529 can prevent the gyrocopter 110 fromrotating about its vertical axis, and/or from rolling forward.

Another feature of an embodiment shown in FIG. 5A is that thepre-rotation torque required for lifting the gyrocopter 110 can beprovided by both off-board and on-board power sources. For example, theoverall system 500 a can include a first on-board transmission device531 a coupled to the on-board power source 114, and a second on-boardtransmission device 531 b coupled to the off-board transmission device146. Using this arrangement, the on-board power source 114 can provideadditional power to the lift rotor 112 to lift the gyrocopter 110without a take-off roll and without pitching the rotor blades 119.

FIG. 5B illustrates a system 500 b configured in accordance with stillanother embodiment of the present technology. In this embodiment, thegyrocopter 110 includes a single on-board transmission device 531 c thatis coupled to both the on-board motor 114 and the off-board pre-rotatorcomponents 140. Accordingly, the system 500 b can include a powercoupling 538 that receives power from both the motor 114 and theground-based components 140, and provides the power to the vehicletransmission device 531 c for pre-rotating the rotor 112.

As is also shown in FIG. 5B, and as was discussed above with referenceto FIG. 4, the vertical restraints have been eliminated. Instead, thefriction provided between the male spline element 137 and the femalespline element 153 are sufficient to keep the on-board transmissiondevice 531 c engaged with the off-board transmission device 146 duringthe rotor spin-up process. Once the female spline element 153 ceasesaccelerating (e.g., at a pre-specified value of rotations per minute),the male spline element 137 disengages as the gyrocopter 110 lifts.

FIG. 6A is a partially schematic, side isometric view of a system 600having a gyrocopter 610 and associated pre-rotator components configuredin accordance with another embodiment of the present technology. In oneaspect of this embodiment, the gyrocopter 610 includes a body 611housing a flight deck 625 (for manned systems) and carrying an on-boardtransmission device 631. The on-board transmission device 631 has anarrangement described in further detail below with reference to FIG. 6C.

The system 600 can further include a base or support 641 having arestraint system 642 that includes lateral restraints 644. The lateralrestraints 644 and vertical restraints 643 are described further belowwith reference to FIG. 6B.

Referring now to FIG. 6B, the lateral restraints 644 can be formed fromcorresponding channels 656 having channel walls 657 that restrict thelateral motion of the gyrocopter wheels 118. The restraint system 642can further include one or more vertical restraints 643 that directlyengage with the wheels 118. For example, the vertical restraints 643 caninclude engagement elements 651 that slide outwardly and inwardly (asindicated by arrows S1 and S2) or rotate outwardly and inwardly (asindicated by arrows R1 and R2) between disengaged and engaged positions.An advantage of the channels 657 shown in FIGS. 6A, 6B is that they canbe simpler to use and/or less obtrusive than the lateral restraints 144discussed above with reference to FIG. 3. The system 600 can furtherinclude on-board and off-board transmission devices 631, 646, describedfurther below.

FIG. 6C is an enlarged view of the rear portion of the gyrocopter 610,illustrating an on-board power source 614 driving a propeller 613. Inaddition, the on-board transmission device 631 can include two links: afirst on-board link 622 a and a second on-board link 622 b. The on-boardlinks 622 a, 622 b can be selectively coupled to each other using gears624 or other suitable coupling devices, and can be selectively engagedor disengaged with each other as indicated by arrow B. When the gears624 are engaged with each other, the off-board transmission device 646provides power to the second on-board link 622 b and the rotor above(not visible in FIG. 6C). When the gears 624 or other coupling elementsare disengaged, the off-board transmission device does not provide powerto the rotor. In such instances, the on-board power source 614 canprovide power to the second on-board link 622 b via a drive link 621. Ina particular embodiment, the drive link 621 can also be selectivelycoupled to or decoupled from the second on-board link 622 b.Accordingly, this arrangement can be used to provide power to the rotorduring a pre-rotator spin-up from the off-board transmission device 646,the on-board power source 614, or both.

FIGS. 7A and 7B are partially schematic, side and front elevation views,respectively, of an existing pre-rotator system (a Bumble Bee gyrocoptersystem, plans available atwww.aircraftdesigns.com/Plans/Bumble-Bee-Plans/flypage_new.tpl.html)that has been retrofitted to support an off-board pre-rotator function,in accordance with yet another embodiment of the present technology.Referring to FIGS. 7A and 7B together, the on-board components of theoverall system 700 can include an on-board power source 714 (e.g., aninternal combustion engine) that provides power to a propeller 713. Afirst pulley 780 a is located behind the propeller 713 and can be usedto transfer power to a second pulley 780 b that is in turn carried by adrive link 721. Accordingly, the two pulleys 780 a, 780 b can transmitpower from the on-board power source 714 to the drive link 721. Thedrive link 721 is in turn coupled to a rotor head assembly 787 (with therotor blades removed for purposes of illustration) to provide apre-rotator function. In particular, the drive link 721 is coupled to agear box assembly or power coupling 738 that transmits the power itreceives to a first on-board link 722, for example, a square tubingdrive shaft. The first on-board link 722 can include a square tubingslip joint 782 or other suitable structure for allowing relativemovement among the components, and a universal joint 784 that is in turncoupled to a pulley/ratchet 785. The pulley/ratchet 785 is in turncoupled to a rotor pulley 786 (via a belt, not shown) that is coupled tothe rotor head assembly 787. The rotor head assembly 787 is carried by amast 783.

The operation of the pre-rotator shown in FIGS. 7A and 7B can becontrolled from on-board the gyrocopter by using an engage/disengagelever 788 that engages or disengages the drive link 721 from the firstpower source 714, e.g., by engaging/disengaging the first and secondpulleys 7801, 780 b. In a particular aspect of the present technology,the system has been retrofitted to include a second on-board link 722 b(e.g., a flexible shaft) that is coupled to the power coupling 781,which has also been retrofitted to accommodate it. The engage/disengagelever 788 (or an additional lever) can also be coupled to the powercoupling 738 (as shown in dashed lines) to engage or disengage thesecond on-board link 722 b from the first on-board link 722 a.Accordingly, the operator can provide pre-rotator power to the rotorhead assembly 787 from the on-board power source 714, or the off-boardpower source (not shown in FIGS. 7A and 7B) via the second on-board link722 b, or via both on-board and off-board power sources.

An advantage of the arrangement shown in FIGS. 7A and 7B is that it canbe versatile, for example, by using the on-board power source 714 whennecessary, and/or off-board power when available. An additionaladvantage of the arrangement shown in FIGS. 7A and 7B is that it can beretrofitted to an existing pre-rotator arrangement.

FIG. 8 is a partially schematic illustration of a portion of a system800 suitable for supporting a gyrocopter having skids or skis 818 (shownin dashed lines) during a pre-rotation operation in accordance with anembodiment of the present technology. In a particular aspect of thisembodiment, the system 800 includes a base 841 carrying a restraintsystem 842 that can be operated via a release mechanism 850. Therestraint system 842 can include multiple hooks or other engagingmembers 855 that can rotate and/or slide (as indicated by arrows P andT, respectively) within and relative to corresponding slots 818 toselectively engage with and disengage from the skids or skis 818. Otheraspects of the operation of the system 800 can be generally similar tothose described above. In still further embodiments, other arrangementscan be used to restrain the gyrocopter during a pre-rotation operation.

FIG. 9 is a flow diagram illustrating a representative method 900 forpre-rotating a gyrocopter rotor for take-off in accordance with anembodiment of the present technology. Block 901 includes restraining thegyrocopter from vertical and lateral movement. As discussed above, oneor more restraining devices can perform this function and, in at leastsome embodiments, the restraining function can be provided at least inpart by system components that also perform the function of spinning upthe gyrocopter rotor.

At block 903, the process includes pre-rotating the fixed-pitch liftrotor of the gyrocopter via a power source located off the gyrocopter.For example, as discussed above, a motor or other power source locatedoff-board the gyrocopter can be releasably coupled to a transmissionsystem carried by the gyrocopter to spin up the gyrocopter rotor. Insome embodiments, the off-board power source can be the sole powersource that spins up the rotor, and in other embodiments, the powerprovided by the off-board power source can be supplemented by powerprovided by an on-board power source. In any of these embodiments, theon-board power source can also be activated so as to provide thrust oncethe gyrocopter has lifted.

At block 905, the method includes interrupting or reducing power fromthe off-board power source to the gyrocopter, e.g., by shutting thepower source down or significantly reducing the output power of thepower source, e.g., to an idle setting. For example, the off-board powersource can include a switch that is thrown to interrupt the power. Theswitch can be triggered manually in some embodiments, and automaticallyin others. For example, a human operator or an automatic controller cantrigger the switch in response to an indication that the rotor speed(tip speed or rotational speed) has met a pre-determined threshold.Representative tip speeds are from about 400 mph to about 450 mph, andrepresentative rotation rates are from about 260 rpm to about 270 rpm orto about 300 rpm.

At block 907, the process includes releasing the gyrocopter for verticalmovement to allow the gyrocopter to lift under the force of the liftrotor. As discussed above, the process of releasing the gyrocopter caninclude actively removing restraints that restrict the gyrocopter fromvertical and lateral movement. In other embodiments, the process ofinterrupting the power from the power source to the gyrocopter can allowthe transmission components that provide the power to the gyrocopter todisengage or release without requiring a separate, active step. Instead,the loss of component acceleration resulting from interrupting orreducing the power can allow the components to release on their own.Once the gyrocopter has lifted a sufficient distance, it begins normalflight operations via the combination of thrust provided by the thrustpropeller, and lift provided by the rotor.

In at least some of the embodiments described above with reference toFIGS. 1-9, the disclosed systems include both on-board (e.g.,ground-based) and off-board (e.g., vehicle-based) pre-rotatorcomponents. By supplying power from off-board the vehicle, the amount ofpower available to pre-rotate the gyrocopter rotor is increased, byvirtue of on the off-board power alone, or the off-board power incombination with power provided on-board the vehicle. In eitherembodiment, the power provided to the gyrocopter rotor is sufficient tolift the gyrocopter without the need for pitch-controlled rotor blades.An advantage of this arrangement is that it can eliminate the complexityand maintenance costs associated with pitchable rotor blades. As aresult, the gyrocopter can take off and land vertically, without theneed for take-off and/or landing ground rolls. Still a further result isthat the gyrocopter can provide a cost-competitive solution forapplications that require or benefit from vertical take-off and landing,without the expense required for pitch control and/or other complexitiesassociated with typical helicopter configurations. Representativeapplications that can benefit from this approach include agriculturalapplications, police or other law enforcement applications, tuna fishingand/or other marine applications, as well as a wide variety of otherpurposes. In particular, the effective range/endurance of the gyrocoptercan be significantly increased because the gyrocopter need not fly froma distance runway to a job site, but can instead take off directly at orvery near the job site.

Another feature of at least some of the foregoing embodiments is thatthe additional power provided by the off-board power source can beprovided by a significantly wider array of available power sources thatif the power source were located on-board the gyrocopter. For example,because the off-board power source is not carried by the gyrocopter, itneed not be lightweight (or at least not as lightweight as componentscarried by the gyrocopter) and need not comply with at least someregulatory requirements that are directed to components carried by thegyrocopter in flight. As a result, the off-board power source can berelatively inexpensive when compared to a corresponding on-board powersource.

From the foregoing, it will be appreciated that specific embodiments ofthe present technology have been described herein for purposes ofillustration, but that various modifications may be made withoutdeviating from the technology. For example, the gyrocopter can be mannedwith an on-board pilot in some embodiments, and can be unmanned inothers. The drive mechanisms described above can have configurationsdifferent than those shown in the foregoing figures, for example, ahydraulic line configuration or other suitable link. The gyrocopteritself can have configurations other than those shown in the Figures. Insome embodiments, as shown above, the releasable connection between theground-based components and the gyrocopter-based components of thepre-rotator system can include a spline having male and femalecomponents. The male component(s) can be carried on-board the gyrocopterand the female component(s) off-board, or vice versa depending on theembodiment. In still further embodiments, the releasable connection caninclude devices other than splines (e.g., spiral gears) that can engageand disengage with or without the aid of an actuator or other activedevice. For example, in some embodiments, the on-board transmissiondevice is coupled to the off-board transmission device via aseparately-activatable device (e.g., a solenoid-driven coupling) thatreleases based on a command from an automated controller, or anin-the-loop operator. The controller can issue the command in responseto an input corresponding to a change in power (e.g., a decrease)provided by the off-board power source.

Certain aspects of the technology described in the context of particularembodiments may be combined or eliminated in other embodiments. Forexample, in some embodiments, some or all of the foregoing componentscan be retrofitted to an existing gyrocopter, and in other embodiments,can be incorporated into a new gyrocopter design. When retrofitted, thecomponents can supplement existing pre-rotator components of thegyrocopter. Further, while advantages associated with certainembodiments of the present technology have been described in the contextof those embodiments, other embodiments may also exhibit suchadvantages, and not all embodiments need necessarily exhibit suchadvantages to fall within the scope of the present technology.Accordingly, the present disclosure and associated technology canencompass other embodiments not expressly shown or described herein.

1. A system for pre-rotating a gyrocopter, comprising: a restraintpositioned to at least restrict lateral and vertical motion of agyrocopter; a power source; and a transmission device coupled to thepower source, the transmission device being releasably coupleable to apre-rotator carried by the gyrocopter. 2-27. (canceled)